I just happened to stumble across a card in my desk drawer with the above title. This is what the card says:
Knot: Represents when you were born. John 3:6
Black: Represents spiritual darkness because of our sin. Rom. 3:23
Red: Represents the Blood Jesus shed to pay the penalty for our sins. Rom. 5: 8-9
White: Represents the cleansing and forgiveness we receive in trusting Christ. 1 John 1:7
Blue: Represents or public profession of Christ through Baptism. Rom. 6: 3-4
Green: Represents our spiritual growth when we pray, worship, read the Bible, etc. Eph. 4:15
Yellow: Represents the glory of Heaven with Christ. Phil. 3: 20-21
Knot: Represents the end of life when everyone will be judged by God. Heb. 9:27